[Qemu-devel] [PATCH COLO-Frame v16 27/35] migration/savevm: Add new helpers to process the different stages of loadvm

[zhanghailiang]

There are several stages during loadvm process. In different stage,
migration incoming processes different section.
We want to control these stages more accuracy, to optimize the COLO
capability.

Here we add two new helper functions: qemu_loadvm_state_begin()
and qemu_load_device_state().
Besides, we make qemu_loadvm_state_main() API public.

Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
---
v16:
- Add Reviewed-by
v14:
- Split from patch 'COLO: Separate the process of saving/loading
  ram and device state
---
 include/sysemu/sysemu.h |  3 +++
 migration/savevm.c      | 38 +++++++++++++++++++++++++++++++++++---
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 8537bed..2e8f397 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -133,6 +133,9 @@ void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, 
const char *name,
                                            uint64_t *length_list);
 
 int qemu_loadvm_state(QEMUFile *f);
+int qemu_loadvm_state_begin(QEMUFile *f);
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
+int qemu_load_device_state(QEMUFile *f);
 
 typedef enum DisplayType
 {
diff --git a/migration/savevm.c b/migration/savevm.c
index e9ddcca..c1f57a6 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1253,8 +1253,6 @@ enum LoadVMExitCodes {
     LOADVM_QUIT     =  1,
 };
 
-static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
-
 /* ------ incoming postcopy messages ------ */
 /* 'advise' arrives before any transfers just to tell us that a postcopy
  * *might* happen - it might be skipped if precopy transferred everything
@@ -1853,7 +1851,7 @@ qemu_loadvm_section_part_end(QEMUFile *f, 
MigrationIncomingState *mis)
     return 0;
 }
 
-static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
 {
     uint8_t section_type;
     int ret;
@@ -1986,6 +1984,40 @@ int qemu_loadvm_state(QEMUFile *f)
     return ret;
 }
 
+int qemu_loadvm_state_begin(QEMUFile *f)
+{
+    MigrationIncomingState *mis = migration_incoming_get_current();
+    Error *local_err = NULL;
+    int ret;
+
+    if (qemu_savevm_state_blocked(&local_err)) {
+        error_report_err(local_err);
+        return -EINVAL;
+    }
+    /* Load QEMU_VM_SECTION_START section */
+    ret = qemu_loadvm_state_main(f, mis);
+    if (ret < 0) {
+        error_report("Failed to loadvm begin work: %d", ret);
+    }
+    return ret;
+}
+
+int qemu_load_device_state(QEMUFile *f)
+{
+    MigrationIncomingState *mis = migration_incoming_get_current();
+    int ret;
+
+    /* Load QEMU_VM_SECTION_FULL section */
+    ret = qemu_loadvm_state_main(f, mis);
+    if (ret < 0) {
+        error_report("Failed to load device state: %d", ret);
+        return ret;
+    }
+
+    cpu_synchronize_all_post_init();
+    return 0;
+}
+
 void hmp_savevm(Monitor *mon, const QDict *qdict)
 {
     BlockDriverState *bs, *bs1;
-- 
1.8.3.1